What was found
AFTER STARTING THE APU & TURNING PACKS ON FOR HEAT THE AFT MIDDLE CABIN STARTED TO FILL W/SMOKE & FUMES. FOUND APU INLET CONTAMINATED WITH HYDRAULIC FLUID DUE TO LEAK FROM RT T/R ACCUMULATOR SUPPLY LINE. SECURED LINE CLEANED AREA AND LEAK CKD. NO OTHER LEAKS FOUND. C/W WORK CARD 2120-2367 USING STEP (14) PER MCC, C/W W/CARD 4950-2215 ALT. DUCT BURN FOR SKYDROL. REPLACED WATER COALESCER BAG PER W/C 2170-4139. NO SMOKE NO FUMES NO SMELL. NO GO ODI 2172 C/W.